This is a part cooler for the Folgertech FT-5 R2 (reportedly does NOT work with R1). It mounts the blower behind the X axis belt and closer to the central axis of the X rail, which minimizes the mass hanging below the X rail and as a result, minimizes the wobble during rapid Y movements. The entire part weighs just 32 grams, and the wall thickness is designed at 0.75mm, which prints fine and is plenty sturdy even in PLA. The airflow has been directed internally by turning vanes in order to achieve a relatively even air output around the ~270 degree air outlet. Also, the air outlet is positioned as close as is reasonably possible to the nozzle, for effective cooling on small parts.
The blower mount attaches to the stock backplate of the carriage via the two lower screws. The stock nylock nuts are removed, the part cooler is put in place, and the screws fasten to the part cooler instead of the nuts. M3 drop-in T-nuts are used inside of the part cooler in order to create a strong attachment to the plastic part that doesn't require the use of a wrench. The nylock nuts have such a small footprint that overtorquing will result in part breakage. The part also features two M3 screw bosses, one each above and below the blower, for installation of screws to push against the backplate in order to finely tune and stabilize the tilt of the air outlet relative to the nozzle. Installation of these screws isn't absolutely necessary... I didn't need them on my latest print of this part, but I may add them to just reduce the amount of flex that the mounting points experience.
I didn't use nuts for fastening screws to the cooler, as I've found that self-threading fine-pitch screws into FDM parts works very well. Holes are sized for a very tight fit, but I recommend reaming M3 threaded holes out to .108" (stabilizing screw bosses), M3 clearance holes out to .120" (part cooler mounting holes), and M4 holes out to .146" (blower mounts). If you don't have those drill sizes, just push HARD and twist screws into the holes to form threads prior to assembly. Take care to support the part well while doing this so you don't break it.
Update: I added a "Reinforced" model with ribs built onto the top of the cooling head because after about 14 hours of printing with my PLA part cooler installed, the right side of the right side of the cooling head has started to sag a bit. Please let me know if the reinforcement ribs prevent this, or if you have any bright ideas to stiffen it without adding too much weight. FYI, I'm running my stock hot end at 210C. In any case, I recommend printing this part in the hottest material you have on hand in order to prevent this. Thanks!
IMPORTANT NOTE: If you use glass or any other top layer on your bed plate, you CANNOT use spring clips (binder clips) to hold it down, especially along the right edge and right half of the rear edge (the FT-5 homes the X axis first). Use low-profile printed clips with ~2mm maximum height off of bed, and manually run the carriage through its limits of travel to check clearance prior to running the printer. As you can see, clearance is very tight, in an effort to get it as close to the part as possible and maximize cooling of the part while minimizing cooling of the heat block (and causing thermal runaway errors).
1x 50x15 24V blower (assumes FT-5 R2 with 24V system)
(sleeve bearings, but you get 2, and they're cheap)
2x M4 x 20mm screws for attaching blower
2x M3 T-nuts for attaching cooler to carriage
I suggest this kit if you don't have any left over from FT-5 assembly:
2x M3 x 20-30mm screws for stabilizing/tweaking position
https://www.amazon.com/iExcell-Stainless-Button-Socket-Screws/dp/B076H2QJ5C (nice assortment)
1) Remove nylock nuts from two lower carriage screws
2) Insert T-nuts (flat side first) into rectangular holes in mounting bosses. I found that using one of the longer M3 screws partially-threaded into the back side of the T-nut works nicely to hang onto the nut while the screw is tightened into it.
3) Tighten carriage screws into T-nuts while hanging onto the screw as suggested above. When threads grab, remove screw from backside of T-nut and finish torquing.
4) Wire up and install blower.
5) Install M3 screws to tweak and stabilize the position of the cooler.
Please let me know how it works out for you! I've included a STEP file for easy re-mixing. Don't you wish everyone would?
Special thanks to Steve Peterson for design feedback and printing expertise! Check out his things... https://www.thingiverse.com/StvPtrsn/about